Figure 1. Comparative effectiveness of unadjuvanted monovalent recombinant vaccines (IAV H7N9 and H1N1) and seasonal trivalent vaccine. Percent effectiveness is shown, as percent of study cohort achieving “significant” seroconversion (see text). The Novartis vaccine company reported that H7N9 cell culture-produced vaccine without adjuvant produced seroconversion rates of 6%.²⁰ In contrast, the rate of seroconversion to unadjuvanted monovalent pandemic H1N1 was 89% in one study.²³ Rates of seroconversion to trivalent seasonal vaccine are 84% on average to the three strains of virus in the vaccine.²⁵